1. Field of the Invention
The present invention relates to disc reproduction apparatuses, and more particularly, to a disc reproduction apparatus including a disc changer function that can have a plurality of discs loaded for sequentially selecting a desired disc for reproduction.
2. Description of the Background Art
Conventional disc reproduction apparatuses with a disc changer function are already proposed such as a disc reproduction apparatus with the so-called roulette type disc changer (refer to Japanese Patent Laying-Open No. 4-10274, for example) that has a plurality of discs mounted annularly on a round disc table, wherein a desired disc is transferred for reproduction to a disc reproduction assembly by a clockwise or counterclockwise rotation of the disc table, or a disc reproduction apparatus with the so-called stacker type disc changer (refer to Japanese Patent Laying-Open No. 3-83262, for example) that selects a desired disc out of a plurality of discs accommodated in a stacker at a predetermined pitch by moving the stacker vertically, whereby the selected disc is chucked by a disc moving means to be transferred to a disc reproduction assembly for reproduction.
The above-described roulette type disc changer had a problem that an increase in the loaded number of discs will increase the diameter of the disc table in proportion to the increased number to significantly increase the size of the apparatus. In order to avoid increase in the size of the apparatus, the number of discs that can be loaded was limited.
In the above-described stacker type disc changer, increase in the thickness of the stacker itself can be suppressed even if the loadable number of discs was increased since discs are accommodated in a stacked manner at a predetermined pitch. However, this type requires a complex operation of moving the stacker vertically for selecting a disc, taking out the selected disc from the stocker, and transferring the disc to the disc reproduction assembly. In order to realize this complex operation, the mechanism becomes complicated with increase in weight of the apparatus.
Furthermore, a disc reproduction apparatus including the above-described two types of disc changer had a problem at set forth in the following when combined with a portable radio cassette tape recorder. In the case of a roulette type disc changer, the disc table becomes too large with respect to the size of the main body of the radio cassette tape recorder. This becomes a bottleneck makes the realization of such a combination difficult. In the case of a stocker type disc changer, such a combination will increase the weight in accordance with the increase of the complexity of the structure, thereby degrading its portability. It is therefore not adaptable for combination with an apparatus that requires portability such as a radio cassette tape recorder.
Japanese Patent Laying-Open No. 60-52951 discloses a disc reproduction apparatus including a draw out mechanism wherein a disc accommodation unit is provided at either side of a disc reproduction assembly for drawing out a disc from the disc accommodation unit, and a disc transport mechanism to move the draw out mechanism vertically for transferring a disc between the disc reproduction assembly and a draw out position in the disc accommodation unit. The apparatus described in this application includes a facility having a disc accommodation unit provided at the rear side of the disc reproduction assembly for transporting one disc selectively to the disc reproduction assembly.
This disc reproduction apparatus had a problem that the size is increased at the upper portion of the disc reproduction assembly to ensure the vertical movement of the disc transport mechanism. There was also the disadvantage of the structure of the disc transportation mechanism and the draw out mechanism becoming complex.
There was also the following disadvantage during the designing stage. In order to exchange a reproduction disc in the apparatus of the above application, first a disc after reproduction is transported to the former accommodated position by the transportation mechanism. That disc is accommodated in a predetermined position in the disc accommodation unit by the draw out mechanism. Then, the transportation mechanism is transported to a predetermined position of the next disc to be reproduced, whereby the disc is drawn out from the disc accommodation portion by a draw out mechanism to be transported to the disc reproduction assembly. Such an operation of disc exchange was time consuming. Furthermore, control of each mechanism in the disc exchange operation was increased in complexity to induce disadvantage in designing.